By Dr. Tessa Sokol – Optometrist, Madison, WI | Sokol Advanced EyeCare
You left your comprehensive eye exam with a shiny new prescription in hand… but what does all of it actually mean?
At Sokol Advanced EyeCare, we believe that eye care should be empowering, not confusing. So today, we’re breaking down exactly how to read your glasses prescription—whether you’re shopping for designer frames, contact lenses, or precision digital lenses.
First: What Your Prescription Format Might Look Like
A glasses prescription typically looks like a grid of numbers and abbreviations. You’ll often see something like this:
SPH CYL AXIS ADD PD
OD | -2.50 | -0.75 | 180 | +2.00 | 31.5
OS | -2.00 | -0.50 | 175 | +2.00 | 31.5
Let’s break it down.
👁️ OD and OS
OD = Oculus Dexter = Right Eye
OS = Oculus Sinister = Left Eye
Sometimes you’ll also see OU (both eyes).
SPH (Sphere)
This tells you the strength of correction needed:
Negative (-) = nearsighted (can’t see far away)
Positive (+) = farsighted (can’t see close-up)
The further from zero, the stronger the correction.
CYL and AXIS
These relate to astigmatism, a common vision issue where the cornea or lens isn’t perfectly round.
CYL (Cylinder) indicates how much astigmatism correction is needed.
AXIS tells us which direction that astigmatism occurs (in degrees, 0 to 180).
Astigmatism is incredibly common and easily corrected with the right lenses.
➕ ADD (Addition)
- This is used for multifocal lenses, such as:
- Progressives
- Bifocals
- Reading glasses
It adds magnifying power to help with close-up tasks (like reading your phone at night or threading a needle).
PD (Pupillary Distance)
This is the distance between your pupils, measured in millimetres. It ensures that your lenses line up perfectly with your eyes.
At Sokol Advanced EyeCare, we take digital PD measurements for the most accurate lens fitting possible—which is especially important when ordering progressive or high-definition lenses.
A Few Things That Don’t Appear—but Matter
Lens recommendations (anti-fatigue lenses, blue-light coatings, transitions)
Lifestyle factors (digital strain, hobbies, night driving)
Frame fit and adjustment
This is why a comprehensive eye exam with an experienced optometrist in Madison, WI is so important—because your prescription is only part of the full picture.
Why We Recommend Getting Lenses at a Eye Clinic (Not Online)
When patients order glasses online using their prescription alone, they’re often missing critical details:
- Custom lens positioning
- Frame adjustments
- Quality of materials
- Optical center alignment
- Warranty and expert fitting
We provide precision lenses, custom digital lens measurements, and designer eyewear that looks as good as it feels.
Does This Apply to Kids, Too?
Absolutely. In pediatric eye care, prescriptions may also include:
- Prism (for eye alignment issues)
- Notes on amblyopia or myopia management
- Monitoring intervals
We also support InfantSEE® eye exams, myopia management, and vision therapy when needed—so your child’s eyes stay healthy as they grow.
Have Questions About Your Prescription?
Whether you’re comparing glasses, need help with contact lens fittings, or just want a second opinion—we’re here to help.
📍 Book a comprehensive eye exam at Sokol Advanced EyeCare, your trusted Madison eye doctor for families, kids, and adults alike.
Or stop by our optical boutique to explore Ray-Ban, Etnia Barcelona, Saint Laurent, and other curated frame lines.
Disclaimer: This blog is for educational purposes only and is not a substitute for personalized medical advice, diagnosis, or treatment. Please consult a qualified healthcare provider with any questions about your eye health or symptoms.
